Endothelial Function and Cardiac Output in RV Pacing

NCT ID: NCT00508196

Last Updated: 2019-03-18

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 22 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2006-11-30
• Study Completion Date: 2007-07-31

Brief Summary

Pacing from the right ventricle (as is current practice in patients implanted with permanent pacemakers for bradycardia), has been associated with worse outcomes particularly in heart failure patients. Recent clinical trials suggest that chronic right ventricular pacing (VP) is associated with worsening heart failure, increased strokes and atrial fibrillation. Hemodynamically, right VP results in delayed activation and contraction of the LV which can give rise to functional mitral regurgitation, shortened diastolic filling time and thus reduced coronary filling, as well as abnormal arterial pulsatile flow. The mechanisms for the deleterious effects of right VP in heart failure patients have not been previously investigated. Our aim of this study is therefore to investigate the hemodynamic effects of right VP in stable heart failure patients in terms of exercise cardiac output (CO, an important measure of myocardial function and prognosis), as well as endothelial function which may be deranged as a result of abnormal arterial pulsatile flow.

Detailed Description

Study Aims The aim of this study is to investigate the effect of right ventricular pacing on CO at rest and exercise, and on endothelial function and B-type natriuretic peptide, BNP, in patients with heart failure.

Methods: Thirty patients with dual chamber pacemakers for sinus node disease will be recruited: 15 controls with normal LV function and 15 with stable impaired LV function (ejection fraction <40%). The pacemaker will be programmed to pace to back-up pacing at 55bpm in the atrial only (AAI, no right VP) for one week (baseline); and than programmed to overdrive pacing at 70-80bpm, randomised to either to dual chamber, DDD (sequential atrial and ventricular pacing) with a short AV delay (to ensure maximal right VP) or AAI (no RV pacing), for 1 week. There will be a crossover after a 1 week washout at backup AAI pacing at 55 bpm. Resting and exercise CO will be measured at the end of each pacing mode intervention using the Inocor system (a validated non invasive method of CO measurement, using inhaled inert gas equilibriums). Endothelial function will be measured non-invasively at the same time points, as will plasma BNP, a measure of LV strain. Patients with unstable heart failure or angina will be excluded.

Study Endpoints: Rest and exercise CO; and endothelial function and BNP with and without RV pacing, in patients with preserved and impaired LV function.

Conditions

Bradycardia

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: TREATMENT
• Blinding Strategy: DOUBLE

Interventions

RVP-min

DDD pacing with long AV delay

Intervention Type: OTHER

RVP-max

DDD pacing with short AV delay

Intervention Type: OTHER

Other Intervention Names

DDD Long; DDD short

Eligibility Criteria

Inclusion Criteria

• Dual chamber pacemaker
• Intact AV node function

Exclusion Criteria

• Unstable angina, heart failure
• Inability to exercise

• Minimum Eligible Age: 21 Years
• Maximum Eligible Age: 85 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University of Dundee

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Allan Struthers, MD

Role: STUDY_DIRECTOR

University of Dundee

Locations

Ninewells Hospital and medical School

Dundee, , United Kingdom

Countries

United Kingdom

Other Identifiers

190906ver3

Identifier Type: -

Identifier Source: org_study_id